Symbology

Viewshed for camera

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# Viewshed for camera
This sample demonstrates how to create a `LocationViewshed` to display interactive viewshed results in the scene view. The viewshed observer is defined by the scene view camera to evaluate visible and obstructed areas of the scene from that location.
<img src="ViewshedCamera.jpg" width="350"/>

Code

// Copyright 2017 Esri.
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
// You may obtain a copy of the License at: http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific
// language governing permissions and limitations under the License.
using Android.App;
using Android.OS;
using Android.Widget;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.UI.Controls;
using Esri.ArcGISRuntime.UI.GeoAnalysis;
using System;
namespace ArcGISRuntime.Samples.ViewshedCamera
{
[Activity]
[ArcGISRuntime.Samples.Shared.Attributes.Sample(
"Viewshed for camera",
"Analysis",
"This sample demonstrates how to create a `LocationViewshed` to display interactive viewshed results in the scene view. The viewshed observer is defined by the scene view camera to evaluate visible and obstructed areas of the scene from that location.",
"", "Featured")]
public class ViewshedCamera : Activity
{
// Create and hold reference to the used MapView
private SceneView _mySceneView = new SceneView();
// URL for a scene service of buildings in Brest, France
private string _buildingsServiceUrl = @"http://tiles.arcgis.com/tiles/P3ePLMYs2RVChkJx/arcgis/rest/services/Buildings_Brest/SceneServer/layers/0";
// URL for an image service to use as an elevation source
private string _elevationSourceUrl = @"http://scene.arcgis.com/arcgis/rest/services/BREST_DTM_1M/ImageServer";
// Location viewshed analysis to show visible and obstructed areas from the camera
private LocationViewshed _viewshedForCamera;
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
Title = "Viewshed camera";
// Create the UI
CreateLayout();
// Create the Scene, basemap, camera, and location viewshed analysis
Initialize();
}
private void Initialize()
{
// Create a new Scene with an imagery basemap
Scene myScene = new Scene(Basemap.CreateImagery());
// Create a scene layer to show buildings in the Scene
ArcGISSceneLayer buildingsLayer = new ArcGISSceneLayer(new Uri(_buildingsServiceUrl));
myScene.OperationalLayers.Add(buildingsLayer);
// Create an elevation source for the Scene
ArcGISTiledElevationSource elevationSrc = new ArcGISTiledElevationSource(new Uri(_elevationSourceUrl));
myScene.BaseSurface.ElevationSources.Add(elevationSrc);
// Add the Scene to the SceneView
_mySceneView.Scene = myScene;
// Set the viewpoint with a new camera focused on the castle in Brest
Camera observerCamera = new Camera(new MapPoint(-4.49492, 48.3808, 48.2511, SpatialReferences.Wgs84), 344.488, 74.1212, 0.0);
_mySceneView.SetViewpointCameraAsync(observerCamera);
// Create a LocationViewshed analysis using the camera as the observer
_viewshedForCamera = new LocationViewshed(observerCamera, 1, 1000);
// Create an analysis overlay to contain the viewshed analysis results
AnalysisOverlay viewshedOverlay = new AnalysisOverlay();
// Add the location viewshed analysis to the analysis overlay, then add the overlay to the scene view
viewshedOverlay.Analyses.Add(_viewshedForCamera);
_mySceneView.AnalysisOverlays.Add(viewshedOverlay);
}
private void UpdateObserverWithCamera(object sender, EventArgs e)
{
// Use the current camera to update the observer for the location viewshed analysis
_viewshedForCamera.UpdateFromCamera(_mySceneView.Camera);
}
private void CreateLayout()
{
// Create a new vertical layout for the app
LinearLayout layout = new LinearLayout(this) { Orientation = Orientation.Vertical };
// Create a button to update the viewshed using the current camera
Button updateViewshedButton = new Button(this);
updateViewshedButton.Text = "Viewshed from here";
updateViewshedButton.Click += UpdateObserverWithCamera;
// Add the button and scene view to the layout
layout.AddView(updateViewshedButton);
layout.AddView(_mySceneView);
// Show the layout in the app
SetContentView(layout);
}
}
}